[Mesa-dev] [Bug 103078] MATLAB broken with mesa software rendering

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=103078

--- Comment #3 from Brian Paul <brianp at vmware.com> ---
Sergio, I installed the 30-day trial of Matlab r2017b and typed 'opengl info'
in the command window.  I did not get a java exception.  I got an error message
that reads:

"""
MATLAB has experienced a low-level graphics error, and may not have drawn
correctly.
Read about what you can do to prevent this issue at Resolving Low-Level
Graphics Issues then restart MATLAB.
To share details of this issue with MathWorks technical support,
please include this file with your service request.
"""

I don't see that issue when using NVIDIA's driver.

I used apitrace to create a trace of Matlab's GL calls with llvmpipe and with
NVIDIA's linux driver.  It looks like Matlab begins by trying to find the
highest supported GL version of the core profile.  With NVIDIA's driver it
finds 4.5.  With llvmpipe it finds 3.3.

Then, it also tries to create compatibility profile context.  With NVIDIA's
driver it again gets a 4.5 context.  With llvmpipe, we don't have such profiles
and Matlab stops after getting a GL 3.1 context.

Finally, with llvmpipe, Matlab tries to create a 3.3 compatibility profile and
fails.  It then successfully creates a legacy context with
glXCreateNewContext().  It calls glGetIntegerv(GL_MAJOR/MINOR_VERSION) then
destroys the context.

As far as I an tell, Matlab simply doesn't accept llvmpipe's context/version
offerings.  Either that's by design or there's some sort of logic bug in MatLab
that gives up on GL support after failing to create a particular kind of
context.

You could try installing some older versions of Mesa to see if Matlab 2016a
works/fails.  But Matlab 2017b seems to act differently.

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/mesa-dev/attachments/20171004/5645216b/attachment.html>